Usmle Step 1

1. Which part of the brain does Parkinson's disease affect?

-neurodegenerative disorder of the substantia nigra and locus ceruleus-depigmentation of substantia nigra pars compacta (loss of dopaminergic neurons)

Cerebellum

Hippocampus

Frontal lobe

Parkinson's disease primarily affects the substantia nigra and locus ceruleus, leading to depigmentation of substantia nigra pars compacta resulting in the loss of dopaminergic neurons.

Explanation

Parkinson's disease primarily affects the substantia nigra and locus ceruleus, leading to depigmentation of substantia nigra pars compacta resulting in the loss of dopaminergic neurons.

2. What symptoms characterize Parkinson's Disease?

Headache, Fever, Nausea, Fatigue

Memory loss, Confusion, Difficulty speaking, Loss of balance

Blurred vision, Dizziness, Joint pain, Shortness of breath

TRAPTremor, Rigidity, Akinesia, Postural instability

Parkinson's Disease is characterized by a group of symptoms commonly remembered as TRAP - Tremor, Rigidity, Akinesia (or Bradykinesia), and Postural instability. These symptoms are caused by the loss of dopamine-producing cells in the brain.

Explanation

Parkinson's Disease is characterized by a group of symptoms commonly remembered as TRAP - Tremor, Rigidity, Akinesia (or Bradykinesia), and Postural instability. These symptoms are caused by the loss of dopamine-producing cells in the brain.

3. What is shown in this brain stain?

Lewy bodies: eosinophilic cytoplasmic inclusions that consist of a dense core surrounded by a halo of 10 nm wide radiating fibrils
-These aggregates are the major feature of PD

Pick bodies: spherical tau protein aggregates seen in Pick's disease.

Alzheimer's plaques: beta-amyloid protein aggregates commonly found in Alzheimer's disease.

Huntington's bodies: intranuclear aggregates of mutant huntingtin protein in Huntington's disease.

The correct answer describes Lewy bodies, which are characteristic cytoplasmic inclusions in Parkinson's disease. The incorrect answers provide information on pathological aggregates seen in other neurodegenerative diseases such as Alzheimer's, Huntington's, and Pick's disease.

Explanation

The correct answer describes Lewy bodies, which are characteristic cytoplasmic inclusions in Parkinson's disease. The incorrect answers provide information on pathological aggregates seen in other neurodegenerative diseases such as Alzheimer's, Huntington's, and Pick's disease.

4. What are Lewy bodies primarily made of?

Beta-amyloid

Prion protein

Tau protein

Alpha-synuclein

Lewy bodies, pathological structures found in certain neurodegenerative disorders like Parkinson's disease, are primarily made of alpha-synuclein protein. Tau protein, beta-amyloid, and prion protein are not the main components of Lewy bodies.

Explanation

Lewy bodies, pathological structures found in certain neurodegenerative disorders like Parkinson's disease, are primarily made of alpha-synuclein protein. Tau protein, beta-amyloid, and prion protein are not the main components of Lewy bodies.

5. How does Duchenne's muscular dystrophy typically present?

Progressive muscle weakness and doesn't have any significant neuropathology

Impaired cognitive function

Abnormalities in sensory nerves

Neurologic symptoms like seizures

Duchenne's muscular dystrophy primarily involves progressive muscle weakness without significant neuropathology. While individuals with the condition may experience some cognitive impairments, sensory nerve abnormalities, or neurologic symptoms, these are not typical features of Duchenne's muscular dystrophy.

Explanation

Duchenne's muscular dystrophy primarily involves progressive muscle weakness without significant neuropathology. While individuals with the condition may experience some cognitive impairments, sensory nerve abnormalities, or neurologic symptoms, these are not typical features of Duchenne's muscular dystrophy.

6. What is the gene disrupted in Duchenne's disease?

Collagen

Dystrophin

Hemoglobin

Insulin

Duchenne's disease is a genetic disorder caused by mutations in the dystrophin gene, leading to the absence or dysfunction of dystrophin protein. Insulin, hemoglobin, and collagen are not directly related to Duchenne's disease.

Explanation

Duchenne's disease is a genetic disorder caused by mutations in the dystrophin gene, leading to the absence or dysfunction of dystrophin protein. Insulin, hemoglobin, and collagen are not directly related to Duchenne's disease.

7. Which part of the brain is primarily affected by Huntington's disease?

Cerebellum

Amygdala

Hippocampus

Primarily the caudate nucleus

Huntington's disease is a neurodegenerative genetic disorder that affects primarily the caudate nucleus, a part of the brain involved in movement control.

Explanation

Huntington's disease is a neurodegenerative genetic disorder that affects primarily the caudate nucleus, a part of the brain involved in movement control.

8. What genetic defect is associated with Huntington's disease?

Deletions in the HTT gene

Chromosomal translocations involving chromosome 4

Single nucleotide mutations in the HTT gene

Trinucleotide repeat expansions inside the Huntingtin protein

Huntington's disease is caused by the expansion of a CAG trinucleotide repeat in the HTT gene, leading to the abnormal elongation of the Huntingtin protein.

Explanation

Huntington's disease is caused by the expansion of a CAG trinucleotide repeat in the HTT gene, leading to the abnormal elongation of the Huntingtin protein.

9. What is Alzheimer's? What is the defect in Alzheimer's disease? What do you see in AD for neuropathology?

1) Rare genetic disorder affecting children 2) Result of viral infection in the brain 3) Presence of excess dopamine levels in the brain

1) most common cause of dementia in the elderly2) mutation in presenilin gene 3) Widespread cortical atrophy; neurofibrillary tangles (tau) and extracellular amyloid plaques

Alzheimer's is not a rare genetic disorder affecting children, caused by a viral infection, or related to excess dopamine levels. The correct answer includes the correct definition, defect, and neuropathological characteristics of Alzheimer's disease.

Explanation

Alzheimer's is not a rare genetic disorder affecting children, caused by a viral infection, or related to excess dopamine levels. The correct answer includes the correct definition, defect, and neuropathological characteristics of Alzheimer's disease.

10. What neurodegenerative disorders are associated with mutations in tau?

-frontotemporal dementia with parkinson linked to chr 17 (FTDP-17)-other neurodegen. disorders including AD, Pick's dz, progressive supranuclear palsy present w/ abnormal cytoplasmic accumulations of tau protein

Epilepsy

Huntington's disease

Multiple sclerosis

Mutations in tau are primarily associated with frontotemporal dementia with parkinson linked to chr 17 (FTDP-17) and other neurodegenerative disorders such as Alzheimer's disease, Pick's disease, progressive supranuclear palsy. Huntington's disease, multiple sclerosis, and epilepsy are not directly linked to mutations in tau.

Explanation

Mutations in tau are primarily associated with frontotemporal dementia with parkinson linked to chr 17 (FTDP-17) and other neurodegenerative disorders such as Alzheimer's disease, Pick's disease, progressive supranuclear palsy. Huntington's disease, multiple sclerosis, and epilepsy are not directly linked to mutations in tau.

11. Who is at an increased risk of developing Alzheimer's disease (AD)?

Individuals who regularly exercise

Individuals with asthma

Down syndrome patients

Individuals who eat a Mediterranean diet

Individuals with Down syndrome have an increased risk of developing Alzheimer's disease due to genetic factors.

Explanation

Individuals with Down syndrome have an increased risk of developing Alzheimer's disease due to genetic factors.

12. What genes are the familial form of Alzheimer's Disease (AD) associated with? What percentage of patients have the familial form?

Late onset: Tau, ApoE4, presenilin-1 15% have familial form

Early onset: APP (21), presenilin-1 (14), presenilin-2 (1)Late onset: ApoE4
10% have familial form

Early onset: Tau, ApoE4, presenilin-2 5% have familial form

Late onset: APP, presenilin-1, presenilin-2 20% have familial form

13. How does Pick's disease (frontotemporal dementia) present?

Muscle weakness and atrophy

Memory loss and disorientation

Dementia, aphasia, parkinsonian aspects; change in personality

Visual hallucinations and delusions

Pick's disease, a type of frontotemporal dementia, typically presents with a combination of symptoms including dementia, aphasia, parkinsonian aspects, and a distinct change in personality. The incorrect answers provided do not align with the common presentation of Pick's disease.

Explanation

Pick's disease, a type of frontotemporal dementia, typically presents with a combination of symptoms including dementia, aphasia, parkinsonian aspects, and a distinct change in personality. The incorrect answers provided do not align with the common presentation of Pick's disease.

14. What histological feature is seen in Pick's disease and which part of the brain does it spare?

1) Lewy bodies (alpha-synuclein aggregates)3) involves the entire brain cortex

2) Neurofibrillary tangles (abnormal tau protein)4) spares frontal lobe and cerebellum

3) Senile plaques (beta-amyloid deposits)5) spares occipital lobe and insular cortex

1) Pick bodies (intracellular, aggregated tau protein)2) spares parietal lobe and posterior 2/3 of superior temporal gyrus

Pick's disease is characterized by the presence of Pick bodies, which are intracellular, aggregated tau proteins. It typically spares the parietal lobe and the posterior two-thirds of the superior temporal gyrus. Unlike the incorrect answers provided, Pick's disease does not involve Lewy bodies, neurofibrillary tangles, or senile plaques, and it does not affect the entire brain cortex, frontal lobe, cerebellum, occipital lobe, or insular cortex.

Explanation

Pick's disease is characterized by the presence of Pick bodies, which are intracellular, aggregated tau proteins. It typically spares the parietal lobe and the posterior two-thirds of the superior temporal gyrus. Unlike the incorrect answers provided, Pick's disease does not involve Lewy bodies, neurofibrillary tangles, or senile plaques, and it does not affect the entire brain cortex, frontal lobe, cerebellum, occipital lobe, or insular cortex.

15. How does Creutzfeldt-Jacob present and what are the histo/gross findings?

1) rapidly progressive (weeks to months)dementia with myoclonus 2) Spongiform cortex; prions (alpha helix to beta sheet)

2) Acute onset dementia with seizures; amyloid plaques

1) Slowly progressive dementia with spastic paralysis; Lewy bodies

3) Chronic headache with visual disturbances; neurofibrillary tangles

Creutzfeldt-Jacob disease typically presents with rapidly progressive dementia along with myoclonus. The histo/gross findings include spongiform cortex and prions converting from alpha helix to beta sheet structure.

Explanation

Creutzfeldt-Jacob disease typically presents with rapidly progressive dementia along with myoclonus. The histo/gross findings include spongiform cortex and prions converting from alpha helix to beta sheet structure.

16. What is dementia?

A disorder marked by an excess of mental clarity and alertness.

An increase in cognitive ability, memory, or function with impaired consciousness.

Decrease in cognitive ability, memory, or function w/ intact consciousness

A condition characterized by physical weakness and fatigue.

Dementia is defined as a decrease in cognitive ability, memory, or function with intact consciousness, not an increase in abilities or physical weakness. It is not a condition marked by excess mental clarity or alertness.

Explanation

Dementia is defined as a decrease in cognitive ability, memory, or function with intact consciousness, not an increase in abilities or physical weakness. It is not a condition marked by excess mental clarity or alertness.

17. What are other causes of dementia outside of AD, Pick's dz, Lewy body dementia (PD w/ dementia and hallucinations), and CJD?

7) Frontotemporal dementia

8) Schizophrenia

6) Huntington's disease

1) Multi-infarct (2nd most common in elderly)2) Syphilis3) HIV4) Vit B12 deficiency5) Wilson's disease

The correct answer provides various other less common causes of dementia outside of the more well-known ones mentioned in the question.

Explanation

The correct answer provides various other less common causes of dementia outside of the more well-known ones mentioned in the question.

18. What is a mainstay treatment for CHF especially when peripheral edema is present?

Corticosteroids

Bronchodilators

Diuresis Ex: Furosemide (most common and effective 1st line treatment); Spironolactone (only one to improve mortality)

Ace Inhibitors

Diuresis is the mainstay treatment for CHF, particularly when peripheral edema is present, as it helps reduce fluid overload and improve symptoms. Ace Inhibitors, Bronchodilators, and Corticosteroids are not typically first-line treatments for CHF.

Explanation

Diuresis is the mainstay treatment for CHF, particularly when peripheral edema is present, as it helps reduce fluid overload and improve symptoms. Ace Inhibitors, Bronchodilators, and Corticosteroids are not typically first-line treatments for CHF.

19. What is acetazolamide? What is it used to treat? What are possible complications? When should it not be given?

1) Beta blocker; 2) Glaucoma, high blood pressure, and acid reflux; 3) Rare complications include liver damage and muscle pain; 4) Avoid in combination with alcohol.

1) Carbonic anhydrase inhibitor 2) glaucoma seizure disorders and acute mountain sickness3) may worsen hepatic encephalopathy, lead to renal calculi, and worsen acidotic states 4) Allergy to sulfa drugs

1) Antibiotic; 2) Asthma, diabetes, and hypertension; 3) Possible side effects include drowsiness, nausea, and rash; 4) Individuals with a history of heart conditions.

1) Antihistamine; 2) Allergies, insomnia, and migraines; 3) Can cause weight gain, dry mouth, and blurred vision; 4) Not recommended for pregnant women.

20. What is mannitol? When is it used? When is it contraindicated?

1) osmotic diuretic2) shock, drug overdose, increased intracranial/intraocular pressure
3) can cause pulmonary edema and contraindicated in CHF

1) antibiotic for bacterial infections 2) used to treat high blood pressure 3) contraindicated in diabetes mellitus

Mannitol is commonly used as an osmotic diuretic in conditions such as shock, drug overdose, and increased intracranial/intraocular pressure. However, it can also cause pulmonary edema and is contraindicated in congestive heart failure (CHF). The incorrect answers provided do not accurately describe mannitol or its uses.

Explanation

Mannitol is commonly used as an osmotic diuretic in conditions such as shock, drug overdose, and increased intracranial/intraocular pressure. However, it can also cause pulmonary edema and is contraindicated in congestive heart failure (CHF). The incorrect answers provided do not accurately describe mannitol or its uses.